The firestorm was fueled in part by the fact that Sacco, who was on a flight without Wi-Fi, couldn't get online to apologize or delete her tweet. Comedian Steve Martin shared an offensive tweet the same evening — but quickly deleted and apologized.

Sacco was getting more attention than a major celebrity.

congrats on this major accomplishment re: #HasJustineLandedYet, Twitter:

/ Via

But while no one person could claim responsibility for turning Biddle's blog item into a storm, Twitter users began to express discomfort with how quickly the situation escalated. Wi-Fi provider GoGo"offered Sacco a direct apology.

On Saturday, IAC announced that it had "parted ways" with Sacco, but asked that she herself not be condemned.

The company wrote in a statement:

The offensive comment does not reflect the views and values of IAC. We take this issue very seriously, and we have parted ways with the employee in question.

There is no excuse for the hateful statements that have been made and we condemn them unequivocally. We hope, however, that time and action, and the forgiving human spirit, will not result in the wholesale condemnation of an individual who we have otherwise known to be a decent person at core.

UPDATE - Dec. 22, 8:51 a.m., ET: Justine Sacco issued an apology, first to a South African newspaper and then to ABC News.

"My greatest concern was this statement reach South Africa first," Sacco said, after sending her statement to South African newspaper The Star, Sacco shared the follow apology with ABC:

Words cannot express how sorry I am, and how necessary it is for me to apologize to the people of South Africa, who I have offended due to a needless and careless tweet. There is an AIDS crisis taking place in this country, that we read about in America, but do not live with or face on a continuous basis. Unfortunately, it is terribly easy to be cavalier about an epidemic that one has never witnessed firsthand.

For being insensitive to this crisis -- which does not discriminate by race, gender or sexual orientation, but which terrifies us all uniformly -- and to the millions of people living with the virus, I am ashamed.

This is my father's country, and I was born here. I cherish my ties to South Africa and my frequent visits, but I am in anguish knowing that my remarks have caused pain to so many people here; my family, friends and fellow South Africans. I am very sorry for the pain I caused.